JP2011080134A - Ozone gas treatment method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ozone gas treatment method which can ensure the deposition of a plating metal in electroless-plating treatment, and further can impart stable adhesion strength to the deposited and plated film by treating the surface of a resin substrate with ozone gas on the optimum condition. <P>SOLUTION: This ozone gas treatment method is a method for treating the surface of the resin substrate with ozone gas by bringing the surface into contact with ozone gas, and includes: a condition-setting step of setting the conditions of a concentration D of the ozone gas, a treatment period of time t and a temperature T of the ozone gas, while using an amount I of the exposure to the ozone gas as an index, which is obtained by the following expression I=D×t×exp(-L/(273.15+T)), (wherein D is the concentration (g/Nm<SP>3</SP>) of the ozone gas; t is the treatment period of time (minute); T is the temperature (°C) of the ozone gas; and L is a temperature coefficient); an exposing step of exposing the surface of the substrate to the ozone gas according to the set condition; and a step of subjecting the exposed surface of the substrate to alkaline treatment. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an ozone gas treatment method in which ozone gas treatment is performed on a substrate surface by exposing ozone gas to the substrate surface of a resin substrate, and in particular, electroless plating treatment is performed on the treated substrate surface. The present invention relates to an ozone gas treatment method that can be suitably performed.

  Conventionally, electroless plating treatment is known as a method for imparting conductivity and gloss to the surface of a resin substrate made of a polymer resin (substrate surface). The electroless plating treatment is a method in which metal ions in a solution are chemically reduced and deposited on the surface of a substrate, and a metal coating (plating coating) is coated on the surface.

  Since such an electroless plating treatment uses a chemical reduction reaction, unlike electroplating that is electrolytically deposited by electric power, the electroless plating treatment is generally performed on the surface of a polymer resin substrate having electrical insulation. However, this is an effective method capable of forming a plating film.

  Moreover, since the base-material surface in which the plating film was formed has electroconductivity, it can also electroplate using electrolytic deposition further. Therefore, it is possible to improve the design by imparting a metallic luster to the surface of a resin base material used in the fields of automobile parts, home appliances, and the like.

  However, the plating film obtained by the electroless plating treatment may not have sufficient adhesion to the substrate. Therefore, as a pretreatment for performing the electroless plating treatment, the substrate surface is subjected to ozone treatment (treatment using ozone water (see, for example, Patent Document 1) or treatment using ozone gas (see, for example, Patent Documents 2 and 3)). There has been proposed a treatment for modifying the surface of a substrate by performing chromic acid treatment or permanganic acid treatment. Of these treatments, ozone treatment is often used. This is because metal plating can be attached without roughening the substrate surface made of resin as compared with other treatments.

JP 2004-131804 A JP-A 63-250468 JP 2005-113162 A

  However, as shown in Patent Document 1, for example, when ozone water treatment is performed on the surface of the substrate, the polymer resin is generated by hydroxy radicals (.OH) that are continuously generated by the reaction between ozone and water. Continue to tear at the molecular level. Thereby, the intensity | strength of the base-material surface and the resin layer of the vicinity of it falls, As a result, the fall of the adhesiveness of a plating film may be caused.

  In view of this point, it is considered that it is an effective method to perform the ozone gas treatment described in Patent Documents 2 and 3, for example, in which hydroxy radicals (.OH) are not generated. However, according to experiments by the inventors, it has been found that even when ozone gas treatment is performed, it is not always possible to stably and stably coat a plating film with high adhesion. In particular, when considering productivity, it is more preferable that the processing time is short, but with this time reduction, even if the plating film is not formed because the plating is not deposited, even if the plating film is formed, It was found that the adhesion strength (adhesion strength) of the plating film may not be sufficient under certain treatment conditions, and a stable plating film cannot always be coated on the substrate surface.

  The present invention has been made in view of such problems. The object of the present invention is to perform an ozone gas treatment on a substrate surface of a resin base material under an optimal condition, thereby performing plating in an electroless plating process. It is another object of the present invention to provide an ozone gas treatment method capable of ensuring that the deposited metal film has a stable adhesion strength.

  In order to solve the above problems, the inventors have made extensive studies. As a result, C = 0 (carbonyl group) is mainly generated as a functional group on the substrate surface after the ozone gas treatment. Since the carbonyl group does not sufficiently penetrate the plating solution into the base material, if C = O is oxidized to a carboxylate such as COONa, the plating solution is easily penetrated into the resin. I got a good knowledge. Therefore, the inventors paid attention to alkali treatment as a subsequent process.

  Furthermore, the inventors, in the course of proceeding the experiment, when performing ozone gas treatment, the ozone gas concentration, treatment time, and ozone gas temperature are parameters that contribute to the progress of the surface modification of the resin substrate, It was considered to be an important parameter that contributes to the deposition of plating in the electroless plating treatment and the adhesion (adhesion strength) of the deposited plating film.

  However, even if these three parameters are set as processing conditions, these parameters affect the modification of the substrate surface in a complex manner. Therefore, each parameter affects the modification of the substrate surface of the resin substrate. It is not clear how much it contributes, and it is difficult to grasp the degree of modification of the substrate surface.

  In particular, when the resin is modified by ozone gas treatment, the deterioration of the resin on the surface of the base material progresses more slowly than when the resin is modified by treatment with ozone water having hydroxy radicals (.OH) described above. . For this reason, when the minimum modification necessary for performing electroless plating is performed, the adhesion strength of the plating film can be secured, but further modification beyond that leads to deterioration of the resin. As a result, the adhesion strength of the plating film decreases. However, when a certain reforming progresses, the deteriorated resin is dissolved by the subsequent alkali treatment, and the brittle resin layer on the substrate surface is sequentially removed, so that the adhesion strength of the plating film is improved.

  Thus, if the progress of the modification of the substrate surface by the ozone gas treatment is insufficient, the plating does not precipitate. Furthermore, since it is slower than the ozone water treatment, it has been found that even if the ozone gas treatment is performed, a condition in which the adhesion strength of the plating film cannot be secured may be established locally.

  Therefore, in order to avoid the setting of processing conditions in which the plating film is deposited and the adhesion strength of the plating film cannot be ensured, the inventors use three parameters: ozone gas concentration, processing time, and ozone gas temperature. The ozone gas exposure amount that can indirectly grasp the modification degree of the base material surface of the material was defined as a new parameter. And the new knowledge that the modification | reformation of the base-material surface suitable for an electroless-plating process could be performed if these three parameters were set based on the exposure amount of ozone gas was acquired.

The present invention is based on the above-mentioned new findings of the inventors, and the ozone gas treatment method according to the present invention is a method of performing ozone gas treatment on the surface of the substrate by bringing ozone gas into contact with the surface of the resin substrate. Because
The following formula I = D × t × exp ((− L / (273.15 + T))
Where D: ozone gas concentration (g / Nm ³ )
t: Processing time (minutes)
T: Ozone gas temperature (° C)
L: A condition setting step for setting the conditions of ozone gas concentration D, treatment time t, ozone gas temperature T using the ozone gas exposure amount I obtained by the temperature coefficient as an index, and the substrate surface according to the set conditions The method includes an exposure step of exposing to ozone gas, and a step of performing an alkali treatment on the exposed substrate surface.

  According to the present invention, the ozone gas concentration D, the treatment time t, and the ozone gas temperature T, which contribute to the degree of modification of the substrate surface in a composite manner, are set to appropriate ranges, using the ozone gas exposure amount I as an index. be able to. Then, by exposing ozone gas to the substrate surface under the set conditions, it is possible to ensure the plating deposition in the electroless plating process and the adhesion strength of the plating film deposited by the electroless plating process.

  In other words, as long as the ozone gas exposure amount I is set at the stage of ozone gas treatment, the degree of modification of the surface of the base material can be indirectly increased in the ozone gas exposure amount I without actually performing electroless plating treatment. Whether or not plating is deposited by electroless plating treatment, and whether or not the adhesion strength of the plating film coated by deposition can be secured even when plating is deposited, I can grasp it.

  Here, as described above, the ozone gas exposure amount I is set within a range in which the plating is deposited and the adhesion strength of the plating film formed by the deposition is ensured in the electroless plating process. It is desirable that the ozone gas exposure amount range can be determined as an optimum range from the parameter values (the ozone gas concentration D, the processing time t, and the ozone gas temperature T) that have been tested in advance.

In addition, exp ((− L / (273 + T)), which is a part of the above-described formula, corresponds to the reaction rate in the ozone gas treatment depending on the temperature. Since the reaction rate is increased, it is derived from the Arrhenius equation shown below.
k = A × exp ((− Ea / R × Ta))

  Here, k: reaction rate constant, A: frequency factor, Ea: activation energy, R: gas constant, Ta: absolute temperature, and A and Ea are values specific to the reaction without depending on temperature.

  Therefore, if K = k / A and Ea / R = L, K = exp (−L / Ta) is obtained, and L can be a temperature coefficient (a constant related to the ozone gas concentration). It is a specific value depending on the resin of the material. Therefore, the temperature coefficient L can be set in an appropriate range in advance through experiments, analysis, or the like.

  Furthermore, by performing alkali treatment on the substrate surface after the exposure step in this way, the carbonyl group on the substrate surface after the ozone gas treatment is oxidized to carboxylate, so in the electroless plating treatment, The plating film can be surely deposited by permeating from the surface of the substrate.

  Furthermore, in the ozone gas processing method according to the present invention, in the condition setting step, it is more preferable to set the conditions in a temperature coefficient L range of 5000 to 10,000.

  According to the present invention, in the range of the temperature coefficient L, the ozone gas concentration D, the treatment time t, the ozone gas temperature T are set, and the ozone gas treatment is performed under the set treatment conditions, thereby modifying the substrate surface. In the electroless plating process, plating can be reliably deposited. That is, from experiments and analysis by the inventors, when the temperature coefficient L is less than 5000 and exceeds 10,000, it is difficult to set the threshold value for plating deposition from the ozone gas exposure amount I (the desired range described above). .

More preferably, in the condition setting step, it is more preferable to set the ozone gas concentration D to 300 g / Nm ³ or less, the treatment time t to 2 to 10 minutes, and the ozone gas temperature T to 20 to 40 ° C.

  According to the present invention, the ozone gas concentration D, the treatment time t, and the ozone gas temperature T that fall within such ranges are set, and the ozone gas treatment is performed under the set treatment conditions, thereby favorably modifying the substrate surface. Can be done.

That is, when the ozone gas concentration D exceeds 300 g / Nm ³ , the generation cost is increased. Further, from the viewpoint of processing efficiency (reforming efficiency), the ozone gas concentration D is more preferably 40 g / Nm ³ or more. Furthermore, when the processing time t is less than 2 minutes, it takes time to stably reach the desired ozone concentration, and when the processing time t exceeds 10 minutes, the viewpoint of productivity. Is not preferable. Further, when the ozone gas temperature T is less than 20 ° C., the ozone gas generator must be provided with a mechanism for cooling the ozone gas. Moreover, since ozone self-decomposes when ozone gas temperature T exceeds 40 degreeC, it is difficult to hold | maintain ozone gas to a higher ozone gas density | concentration.

  The polymer resin on the substrate surface for performing the ozone gas treatment method according to the present invention is preferably a resin having an unsaturated bond such as a C═C bond, a C═N bond, or a C≡C bond. As the resin possessed, ABS resin, AS resin, PS resin, AN resin, epoxy resin, PMMA resin, polyimide resin, polyphenyl sulfide resin, and the like can be used.

However, more preferably, the surface of the base material on which the ozone gas treatment method according to the present invention is performed is made of ABS resin, and the ozone gas exposure amount I when the temperature coefficient is 6000 in the condition setting step. Is set to 3.3 × 10 ^{−7 to} 1.0 × 10 ⁻⁶ , or 3.0 × 10 ⁻⁶ or more.

  According to the present invention, when the substrate surface is made of an ABS resin, the ozone gas concentration D, the processing time t, and the ozone gas temperature T are set so that the ozone gas exposure amount I falls within the above range. Plating can be reliably deposited at the time of electrolytic plating, and furthermore, adhesion strength of the deposited plating film can be ensured.

That is, when the ozone gas exposure amount I is less than 3.3 × 10 ⁻⁷ , plating cannot be deposited in the electroless plating process. This is because the substrate surface of the resin substrate is not sufficiently modified by the ozone gas treatment. Moreover, when the ozone gas exposure amount I exceeds 1.0 × 10 ⁻⁶ and less than 3.0 × 10 ⁻⁶ , the adhesion strength of the plating film is lowered. This is considered to be caused by the progress of resin deterioration due to the modification of the substrate surface by the ozone gas treatment. However, in the case of 3.0 × 10 ⁻⁶ or more, a certain reforming proceeds, and the degraded resin is dissolved by the subsequent alkali treatment, and the embrittled resin layer on the substrate surface is sequentially removed. The adhesion strength of the plating film is improved.

  Moreover, as another aspect, the ozone gas treatment method according to the present invention is a method of performing ozone gas treatment on the surface of the resin base material by bringing ozone gas into contact with the surface of the resin base material. It comprises an exposure step of exposing the substrate surface of the material to the ozone gas, and a step of performing an alkali treatment on the exposed substrate surface.

  According to the present invention, the carbonyl group on the substrate surface after the ozone gas treatment is oxidized to a carboxylate by performing an alkali treatment on the substrate surface after the exposure step. The plating film can be surely deposited by permeating from the surface of the substrate.

  According to the present invention, by performing ozone gas treatment on the base material surface of the resin base material under optimum conditions, in the electroless plating treatment, the deposition of the plating is ensured, and the deposited plating film is stable. It can have adhesion strength.

The flowchart for demonstrating the ozone gas processing process and electroless-plating process which concern on this embodiment. Schematic of the ozone gas processing apparatus for enforcing the ozone gas processing method which concerns on this embodiment. The figure for demonstrating the ozone gas density | concentration which concerns on an Example. The figure which showed the relationship between the ozone gas density | concentration which concerns on an Example, and adhesion strength.

  Below, with reference to drawings, the plating method to the resin base material including the ozone gas processing method which concerns on this invention is demonstrated based on embodiment. FIG. 1 is a work flow diagram for explaining each step of the plating method according to the present embodiment.

  As shown in FIG. 1, a molding step S11 for molding a base material (resin base material) from a polymer resin having an unsaturated bond, such as an ABS resin, is performed. The molding method of the substrate is not particularly limited, and various molding methods such as compression molding, extrusion molding, blow molding and injection molding can be employed.

Next, the process proceeds to a processing condition setting step (condition setting step) S12. Here, using the following equation (1), the ozone gas exposure amount I is used as an index to set the conditions of ozone gas concentration D (g / Nm ³ ), treatment time t (minutes), and ozone gas temperature T (° C.). .
I = D × t × exp ((− L / (273.15 + T)) (Formula 1)

Specifically, ozone gas exposure conditions (ozone gas concentration D (g / Nm ³ ), treatment time t (min), and ozone gas temperature at which the plating film is deposited and the adhesion strength of the plating film becomes a desired adhesion strength. The condition (T (° C.) changed) is extracted in advance by experiments or the like, and this condition is substituted into Equation 1 to calculate the ozone gas exposure I.

  In this way, by calculating the ozone gas exposure amount I from an experiment in advance, the ozone gas concentration D, the treatment time t, and the ozone gas temperature T that contribute to the degree of modification of the surface of the base material in a complex manner are appropriately set in the actual line. Can be set in the condition. That is, as long as the ozone gas exposure amount I satisfying the above conditions is set using Equation 1 at the stage of ozone gas treatment, the degree of modification of the surface of the substrate can be achieved without actually performing electroless plating treatment. Whether the plating is deposited by electroless plating treatment, and whether the adhesion strength of the plating film coated by the deposition can be secured even if the plating is deposited. Can grasp.

In the condition setting step, the ozone gas concentration D is 40 to 300 g / Nm ³ or less, the treatment time t is 2 to 10 minutes, the ozone gas temperature T is 20 to 40 ° C., the temperature coefficient L is 5000 to 10,000, A processing time t and an ozone gas temperature T are set.

When the ozone gas concentration D is less than 40 g / Nm ³ , the processing efficiency (reforming efficiency) decreases, and when it exceeds 300 g / Nm ³ , the production cost increases. Further, from the viewpoint of processing efficiency (reforming efficiency), the ozone gas concentration D is more preferably 40 g / Nm ³ or more. Furthermore, when the processing time t is less than 2 minutes, it takes time to stably reach the desired ozone concentration, and when the processing time t exceeds 10 minutes, the viewpoint of productivity. Is not preferable. Also, from the experiments and analysis by the inventors, when the temperature coefficient L is less than 5000 and exceeds 10,000, the threshold value for the plating deposition possibility (range of the above-mentioned desirable ozone gas exposure amount) is set from the ozone gas exposure amount. It becomes difficult.

In particular, according to experiments conducted by the inventors shown in Examples to be described later, when the substrate surface is made of ABS resin, in the condition setting step, the temperature coefficient is set to 6000, and the range of the ozone gas exposure amount I is 3 The ozone gas concentration D, the processing time t, and the ozone gas temperature T are set so as to be 3 × 10 ^{−7 to} 1.0 × 10 ⁻⁶ or 3.0 × 10 ⁻⁶ or more.

That is, when the ozone gas exposure amount I is less than 3.3 × 10 ⁻⁷ , plating cannot be deposited in the electroless plating process. Moreover, when the ozone gas exposure amount exceeds 1.0 × 10 ⁻⁶ and is less than 3.0 × 10 ⁻⁶ , the adhesion strength of the plating film decreases.

  In this manner, in the treatment condition setting step S12, the ozone gas concentration D, the treatment time t, and the ozone gas temperature T are used as exposure conditions, with the set ozone gas exposure amount I as an index, on the substrate surface of the resin base material molded in S11. On the other hand, exposure treatment of ozone gas is performed.

  FIG. 2 is a schematic diagram of an ozone gas processing apparatus for carrying out the ozone gas processing method according to the present embodiment, and ozone gas exposure processing step S13 is performed using this ozone gas processing apparatus. Specifically, a raw material gas supply source 11 filled with a mixed gas (for example, a mixed gas of 5% by volume of nitrogen gas) mixed by an industrial oxygen gas cylinder and an industrial nitrogen gas cylinder is prepared. Next, the source gas supply source 11 is supplied to the ozone generator 12 to generate ozone gas having a desired ozone concentration and temperature.

  Next, at this time, the valve 31, the valve 32, and the three-way valve 33 are adjusted to adjust the ozone gas flow rate so that a desired flow rate is obtained, and the flow meters 22 and 23 and the pressure gauge at that time are adjusted. The values 21 and 24 are measured. Furthermore, the ozone gas concentration meter 35 measures the supply ozone gas concentration. The three-way valve 33 is set so as to flow to the ozonolysis device 27.

  Next, the resin substrate W, which is an object to be processed, is installed in the reaction tank 50, the reaction tank 50 is immersed in the water bath 52, and the reaction tank 50 is also adjusted to the target gas temperature. Then, after the adjustment to the target ozone gas concentration D and ozone gas temperature T set in S12, the three-way valve 34 is turned so that the ozone gas flows into the reaction tank 50. In addition, the processing time of ozone gas at this time is set to 0 minutes from the processing time start. At this time, the temperature in the reaction vessel is measured with the thermometer 28 until the set processing time t is reached, and the ozone gas concentration at the outlet of the reaction vessel is measured with the ozone gas concentration meter 26.

Thereafter, when the set processing time t is reached, the three-way valve 33 is turned so as to flow into the ozone gas decomposing apparatus 27, and further, the valve 33 is opened so that the nitrogen gas flows, and the three-way valve is turned so as to Gas is sent into the reaction vessel. By ozone concentration meter 26, the ozone gas concentration at the outlet of the reaction vessel 50, confirm that became almost 0 g / Nm ^3, opening the reaction vessel, taking out the resin substrate. In this way, the ozone gas exposure treatment step S13 is performed.

  Next, alkali treatment process S14 is performed. In this alkali treatment step S14, an alkali solution containing at least a surfactant is brought into contact with the treated surface after the ozone gas treatment. Surfactant is for improving the adsorption property of the palladium catalyst mentioned later, and can mention anionic surfactants, such as sodium lauryl sulfate. Examples of the alkali component of the alkali solution include sodium hydroxide, potassium hydroxide, lithium hydroxide, and the like. Alkali metal can be applied to the treated surface (the carbonyl group on the substrate surface after the ozone gas treatment is oxidized to a carboxylate).

  Furthermore, it is desirable to use a polar solvent as the solvent of the solution containing the surfactant and the alkali component, and water can be used as a representative, but in some cases, an alcohol solvent or a water-alcohol mixed solvent is used. May be. Moreover, in order to make an alkaline solution contact with a resin base material, the method of immersing a resin base material in a solution, the method of apply | coating a solution to the surface by spray etc. can be mentioned.

  Next, the catalyst adsorption processing step S15 is performed. In the catalyst adsorption treatment step S15, the treated surface subjected to alkali treatment is immersed in a catalyst solution (catalyzer) in which palladium chloride and tin chloride are dissolved in an aqueous hydrochloric acid solution. Thereby, a palladium catalyst is made to adsorb | suck to the process surface of a base material. Then, the treatment surface is brought into contact with an acidic solution to activate the palladium catalyst.

  Examples of the metal catalyst to be adsorbed on the surface of the resin substrate made of a polymer resin include metal catalysts such as palladium, silver, cobalt, nickel, ruthenium, cerium, iron, manganese, and rhodium. A combination of these may also be used.

  Next, the electroless plating treatment step S16 is performed on the surface of the base material on which the catalyst is adsorbed. Specifically, in the electroless plating treatment step S16, a nickel plating solution is immersed in the treated surface after the catalyst adsorption treatment to deposit nickel on the surface, and the treated surface subjected to the catalyst adsorption treatment is subjected to no treatment. An electrolytic nickel plating film is formed. Further, an electroplating treatment step S17 is performed on the surface of the electroless nickel plating film. Specifically, it is immersed in a copper sulfate electroplating bath and copper plating is deposited by electroplating.

  In this way, as a pretreatment step of the electroless plating treatment step, by performing ozone gas treatment on the substrate surface of the resin base material under the optimum conditions using the ozone gas exposure amount I as an index, in the electroless plating treatment, It is possible to ensure the precipitation, and the deposited plating film can have a stable adhesion strength.

The present invention will be described below based on examples. In addition, the Example shown below is one Example of this invention, and this invention is not interpreted limitedly.
[Example 1]
[Processing condition setting process]
First, a plurality of test pieces (50 mm × 100 mm × t 3 mm, with a handle (10 mm × 20 mm × t 3 mm) molded from ABS resin were prepared as a resin base material, and then I = D × t × exp ((− L /(273.15+T)) (D is ozone gas concentration (g / Nm ³ ), t is treatment time (minutes), T is ozone gas temperature (° C.), and L is temperature coefficient 6000). Table 1 shows ozone gas exposure amount I as an index so that the range of exposure amount I is 3.3 × 10 ^{−7 to} 1.0 × 10 ⁻⁶ or 3.0 × 10 ⁻⁶ or more. As described above, the treatment conditions of ozone gas concentration D, treatment time t, and ozone gas temperature T were set, and the ozone gas exposure amount I ranged in advance through a series of treatment steps, and plating was deposited by electroless plating treatment. And then It is the range of the calculated ozone gas exposure amount from the conditions when the adhesion strength of the deposited plating film is ensured, provided that the following processing conditions are different from the conditions previously performed to obtain this range. Yes.

[Exposure treatment process]
Next, an ozone gas exposure treatment step was performed under the treatment conditions (exposure conditions) shown in Table 1 using an apparatus similar to the ozone gas treatment apparatus shown in FIG. Oxygen gas and nitrogen gas were mixed using an industrial oxygen gas cylinder and an industrial nitrogen gas cylinder, and a mixed gas (so that the nitrogen gas was 5% by volume) was used as a raw material for ozone gas.

  And the ozone gas produced | generated using the ozone generator (Sumitomo Precision Industries Co., Ltd. product GR-RD) was flowed to the reaction container (1 L all-fluororesin cylindrical container). More specifically, a three-way valve (corresponding to the three-way valve 33 in FIG. 2) directly connected to the ozone generator is allowed to flow to the ozone decomposition device, and an ozone gas having an arbitrary ozone gas concentration is flowed at 0.6 NL / min. Was generated.

  Next, the resin base material was installed in the reaction vessel, and the reaction vessel was immersed in a water bath (Cool Ace CA-1111 manufactured by Tokyo Rika Kikai Co., Ltd.), and the inside of the reaction vessel was adjusted to the set temperature. In addition, in order to measure the concentration of ozone gas in the reaction tank, the ozone gas concentration at the inlet (supply ozone concentration) and the ozone gas concentration at the outlet (ozone concentration in the tank) are each ozone concentration meters (inlet and outlet: manufactured by Sugawara Jitsugyo Co., Ltd.) EG-600).

Then, as shown in Table 1, when the ozone gas temperature and the ozone gas concentration were adjusted, the above-described three-way valve was turned to allow the ozone gas to flow into the reaction vessel. The time was set as the processing time t = 0 minutes. Thereafter, after the processing time shown in Table 1 was reached, the ozone gas to be supplied was caused to flow to the ozonolysis apparatus side with a three-way valve, and nitrogen gas was allowed to flow to the reaction tank (specifically, about Nitrogen gas was flowed at 5 NL / min for 2 minutes). After confirming that the ozone gas at the outlet of the reaction vessel was approximately 0 g / Nm ³ with an ozone gas concentration meter, the reaction vessel was opened and the resin base material was taken out.

  Regarding the ozone gas concentration, the average ozone gas concentration in the tank was used as a parameter. The supply ozone gas concentration shown in Table 1 is the ozone gas concentration at the inlet of the tank, and is almost the same as the concentration immediately after the ozone gas is generated. However, the ozone gas concentration that contributes to the reforming of the ABS resin is the concentration in the treatment tank and is not the same as the supply ozone gas concentration. Therefore, the outlet ozone gas concentration was set as the ozone gas concentration in the tank. Since the ozone gas concentration in the tank changes with the processing time, the numerical value must be determined by some method. Therefore, as shown in FIG. 3, the average value of the ozone gas concentration in the tank that was monitored was set as the average ozone gas concentration (that is, the ozone gas concentration that contributed to the surface modification), and this was used to determine the ozone gas exposure amount I. Was calculated. Specifically, the relationship shown in Table 1 below was obtained.

[Alkali treatment process]
A mixed aqueous solution containing sodium lauryl sulfate (50 g / L) and NaOH (1 g / L) was prepared. The ozone-treated ABS resin base material was immersed in this mixed aqueous solution set at 50 ° C. for 2 minutes. Then, the resin base material was taken out from the aqueous solution and washed with water.

[Catalyst adsorption process]
As a catalyst adsorption treatment step, a catalyst solution in which palladium chloride (0.1% by mass) and tin chloride (5% by mass) are dissolved in an aqueous hydrochloric acid solution (3N), at a treatment temperature of 40 ° C. and an immersion time of 4 minutes. The resin base material after alkali treatment was immersed. Then, in order to activate palladium, the resin base material was immersed for 2 minutes in hydrochloric acid aqueous solution (1N). The temperature of the aqueous hydrochloric acid solution was set to 50 ° C. In this way, the catalyst was adsorbed on the surface of the ABS resin substrate. Thereafter, the resin base material was taken out and washed with water.

[Plating process]
First, as an electroless plating treatment step, a resin base material is immersed for 10 minutes in a Ni-P chemical plating bath (plating solution) kept at 30 ° C., and a Ni-P plating film is formed on the surface of the resin base material. Formed. And uniform plating precipitation was confirmed by the resin base material processed in this way. At this time, the thickness of the formed plating film was 0.5 μm. Furthermore, as an electroplating process, a copper plating film is further formed on the surface of the electroless Ni—P plating film in a copper sulfate electroplating bath (25 ° C., 40 minutes), and electroless Ni—P plating is performed. A copper plating film was further coated on the film.

[Comparative Example 1]
The same procedure as in Example 1 was performed from the ozone gas setting step to the electroless plating step. The difference from Example 1 is that the ozone gas exposure amount I is less than 3.3 × 10 ⁻⁷ as shown in Table 1. In this case, deposition of plating could not be confirmed in the electroless plating treatment process.

[Comparative Example 2]
The same procedure as in Example 1 was performed from the ozone gas setting step to the plating step (electroplating). As shown in Table 2, the difference from Example 1 is that the ozone gas exposure amount I exceeds 1.0 × 10 ⁻⁶ and less than 3.0 × 10 ⁻⁶ .

[Comparative Example 3]
The same procedure as in Example 1 was performed from the ozone gas setting step to the electroless plating step. The difference from Example 1 is that the alkali treatment step was not performed. In this case, deposition of plating could not be confirmed in the electroless plating treatment process.

[Adhesion strength test]
In order to evaluate the adhesion strength of the electroless plating film on the resin substrate, the tensile tests of Example 1 and Comparative Example 2 were performed under the following conditions. A notch on a strip having a width of 10 mm was made in the plating film on the resin base material, and the adhesion strength (peel strength) of the plating film was measured according to JIS H8630 (adhesion test method) using the test piece. The results are shown in Table 2 and FIG. FIG. 4 shows the relationship between the ozone gas exposure amount I and the ozone gas concentration. Moreover, since the electroless Ni-P plating film is not formed in Comparative Examples 1 and 3, the adhesion strength test is not performed.

[Result 1 and Discussion 1]
As shown in Table 2, in Example 1, plating was deposited in the electroless plating treatment step, but in Comparative Example 1, plating was not deposited in the electroless plating treatment step. This is because when the ozone gas exposure amount I in the treatment condition setting step of Comparative Example 1 is less than 3.3 × 10 ⁻⁷ , the base material surface of the resin base material is not sufficiently modified with ozone gas. It is believed that there is.

[Result 2 and Discussion 2]
As shown in FIG. 4, the peel strength of the plating film of Example 1 was always ensured to be 1.00 kg / cm or more, but the peel strength of the plating film of Comparative Example 2 varies, and is 1.00 kgf. Many were less than / cm. This is considered to be because when the ozone gas exposure amount I exceeds 1.0 × 10 ⁻⁶ and is less than 3.0 × 10 ⁻⁶ , the adhesion strength of the plating film is reduced. This is considered to be caused by the progress of resin deterioration due to the modification of the substrate surface.

However, when the ozone gas exposure amount I of Example 1 is 3.0 × 10 ⁻⁶ or more, a certain reforming progresses, and the alkali treatment thereafter dissolves the deteriorated resin, and the substrate surface becomes brittle. Since the formed resin layer is sequentially removed, it is considered that the adhesion strength of the plating film is improved. Therefore, it is considered that the peel strength (adhesion strength) becomes constant if the ozone gas exposure amount I is further increased.

[Result 3 and Discussion 3]
In Comparative Example 3, no plating was deposited in the electroless plating treatment. In the case of Example 1, since the carbonyl group on the substrate surface after the ozone gas treatment is oxidized to a carboxylate by performing an alkali treatment on the substrate surface after the exposure step, in the electroless plating treatment The plating solution was allowed to permeate from the substrate surface, and the plating film could be reliably deposited. In the case of Comparative Example 3, the plating solution was allowed to remain on the substrate surface with the carbonyl group remaining on the substrate surface after the ozone gas treatment. It is considered that the plating film did not precipitate because it was not possible to permeate.

Thus, as shown in Example 1, the range of the ozone gas exposure amount I is 3.3 × 10 ^{−7 to} 1.0 × 10 ⁻⁶ , or 3.0 × 10 ⁻⁶ or more. If the above conditions are set, the ozone gas concentration D, the processing time t, and the ozone gas temperature T can be set to the desired modified state (electroless plating treatment process) In this case, it can be easily set so that plating is deposited and the strength of the plating film can be ensured at a desired strength), and a suitable electroless plating treatment can be performed.

[Examination of temperature coefficient L]
Here, from the exposure conditions shown in Table 2 and the results of plating deposition, the maximum value of the ozone gas exposure amount I under all test conditions (Comparative Example 1) where plating did not deposit is the ozone gas under all test conditions where plating was deposited. A temperature coefficient L was calculated when a condition not exceeding the minimum value of the exposure amount I was satisfied. As a result, the temperature coefficient is in the range of 5000 to 1000 (specifically, 5813 to 9180), that is, at least if the temperature coefficient is within this range, the above-described equation of ozone exposure I indicates that It is thought that precipitation can be determined.

  Although one embodiment of the present invention has been described in detail above, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention described in the claims. Design changes can be made. In this embodiment, the ozone gas exposure treatment was performed after setting the treatment conditions. For example, the amount of ozone gas exposure by which plating is deposited and the adhesion strength of the plating film can be ensured is investigated in advance through experiments or the like. If so, before performing the electroless plating treatment, calculate the ozone gas exposure amount from the ozone gas concentration, treatment time, and ozone gas temperature, and based on this ozone gas exposure amount, judge the plating deposition and judge the adhesion strength of the plating film Etc. can be performed.

  S11: Molding step, S12: Treatment condition setting step, S13: Ozone gas exposure treatment step, S14: Alkali treatment step, S15: Catalyst adsorption treatment step, S16: Electroless plating treatment step, S17: Electroplating treatment step

Claims (4)

A method of performing ozone gas treatment on the surface of the substrate by contacting ozone gas with the surface of the resin substrate,
The following formula I = D × t × exp ((− L / (273.15 + T))
Where D: ozone gas concentration (g / Nm ³ )
t: Processing time (minutes)
T: Ozone gas temperature (° C)
L: a condition setting step for setting the ozone gas concentration D, the processing time t, and the ozone gas temperature T using the ozone gas exposure amount I obtained by the temperature coefficient as an index;
According to the set conditions, an exposure step of exposing the substrate surface to the ozone gas;
And a step of performing an alkali treatment on the exposed substrate surface.   2. The ozone gas processing method according to claim 1, wherein in the condition setting step, the condition is set in a temperature coefficient L range of 5000 to 10,000. The substrate surface is made of ABS resin, and the ozone gas exposure amount I ranges from 3.3 × 10 ^{−7 to} 1.0 × 10 ⁻ when the temperature coefficient is set to 6000 in the condition setting step. ^6, or, so that 3.0 × 10 ^-6 or more, the ozone gas processing method according to claim 2, characterized in that the setting of the condition. A method of performing ozone gas treatment on the surface of the substrate by contacting ozone gas with the surface of the resin substrate,
An exposure step of exposing the substrate surface of the resin substrate to the ozone gas;
And a step of performing an alkali treatment on the exposed substrate surface.

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